Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Since the magnitude of the response to a drug may depend upon the drug input rate, the concentration-effect relationship of the new dihydropyridine (+/-)-isradipine was investigated using different administration modalities. Ten normotensive healthy volunteers were given, double-blind and in a crossover fashion, isradipine as a 1 mg iv infusion, 5 mg oral solution, 5 mg standard tablet, 10 mg slow release formulation, and a placebo. Blood pressure, heart rate, and plasma isradipine concentrations were recorded for 24 h. The maximal fall in diastolic blood pressure was similar after the infusion (-11.40 mmHg), the oral solution (-15.20 mmHg), and the standard tablet (-12.50 mmHg). In healthy volunteers the slow release form had no significant effect on blood pressure. The concentration-effect plots showed an increasing slope in the order infusion, solution, and table, and anticlockwise hysteresis. This was partly due to marked heart rate counter-regulation, the corresponding mean maximal heart rate increases being 24, 19, and 17 beats.min-1. The pronounced counter-regulation of the heart rate implies that a slow isradipine input rate would be more effective in decreasing blood pressure.

Original publication





European journal of clinical pharmacology

Publication Date





29 - 33


Division of Clinical Pharmacology, University Hospital, Geneva, Switzerland.


Humans, Isradipine, Delayed-Action Preparations, Tablets, Solutions, Administration, Oral, Infusions, Intravenous, Double-Blind Method, Blood Pressure, Heart Rate, Dose-Response Relationship, Drug, Stereoisomerism, Half-Life, Adult, Male, Hemodynamics